Anything could have caused the cat to loss his tooth. If your cat has really
smelly breath it could be a sign of an abscess. The spot that he lost his
tooth could have an under lying infection. Best thing is to do what you are
doing.
Personally I would tell your wife and son it is money well spent they don't
like it tell them tough sh@t how would they like it next time that they are
hury and you told them they were not going to see a doctor